, Volume 169, Issue 2, pp 198–204 | Cite as

Expectations and placebo responses to caffeine-associated stimuli

  • Magne Arve Flaten
  • Ole Aasli
  • Terry D. Blumenthal
Original Investigation



To test the theory that expectations control placebo responses.


Subjects (n=20) were asked how much they expected their arousal to increase after one or two cups of coffee, and were subsequently exposed to one or two cups of decaffeinated coffee, or to caffeine equivalent to one or two cups of coffee (200 and 400 mg). The expectancy theory of placebo responses predicts a positive correlation between expectations and actual placebo responses.


Dependent variables were acoustic startle eyeblink and skin conductance responses, blood pressure and heart rate, and measures of subjective arousal.


Caffeine increased startle eyeblink and skin conductance responses, as well as blood pressure and subjective arousal. Decaffeinated coffee increased startle eyeblink and skin conductance responses, but had no effect on subjective arousal, although the participants clearly expected increased subjective arousal after both one and two cups of coffee. However, there were significant correlations between the alertness expected after coffee, and the actual alertness recorded after decaffeinated coffee.


The main finding in this study was that relatively strong expectations about the effects of coffee did not generate placebo responses after administration of decaffeinated coffee. Expectations were dose dependent, whereas the placebo response was not. However, expected alertness after coffee predicted recorded alertness after coffee. In sum, the expectancy theory of placebo effects received only limited support.


Placebo response Caffeine Expectation Classical conditioning Startle Skin conductance 



This research was funded by a grant from the Norwegian Science Council (project no. 142540/320) to Dr. Flaten.


  1. Benedetti F, Amanzio M, Baldi S, Casadio C, Cavallo A, Mancuso M, Ruffini E, Oliaro A, Maggi G (1998) The specific effects of prior opioid exposure on placebo analgesia and placebo respiratory depression. Pain 75:313–319CrossRefPubMedGoogle Scholar
  2. Blanchard J, Sawers SJA (1983) Comparative pharmacokinetics of caffeine in young and elderly men. J Pharmacokinet Biopharmaceut 11:109–126Google Scholar
  3. Bond A, Lader M (1974) The use of analogue scales in rating subjective feelings. Br J Med Psychol 47:211–218Google Scholar
  4. Flaten MA (1993) A comparison of electromyographic and photoelectric techniques in the study of classical eyeblink conditioning and startle reflex modification. J Psychophysiol 7:230–237Google Scholar
  5. Flaten MA, Blumenthal TD (1999) Caffeine-associated stimuli elicit conditioned responses: an experimental model of the placebo effect. Psychopharmacology 145:105–112Google Scholar
  6. Griffiths RR, Woodson PP (1988) Caffeine physical dependence: a review of human and laboratory animal studies. Psychopharmacology 94:437–451PubMedGoogle Scholar
  7. Knowles JB (1963) Conditioning and the placebo effect: the effects of decaffeinated coffee on simple reaction time in habitual coffee drinkers. Behav Res Ther 1:151–157CrossRefGoogle Scholar
  8. Lane JD (1997) Effects of brief caffeinated-beverage deprivation on mood, symptoms, and psychomotor performance. Pharmacol Biochem Behav 58:203–208PubMedGoogle Scholar
  9. Lienert GA (1956) Die Bedeutung der Suggestion in pharmakopsychologischen Untersuchungen. Zeit Exp Ang Psychol 4:418–438Google Scholar
  10. Lykken DT (1972) Range correction applied to heart rate and GSR data. Psychophysiology 9:373–379PubMedGoogle Scholar
  11. Mikalsen A, Bertelsen B, Flaten MA (2001) Effects of caffeine, caffeine-associated stimuli, and caffeine-related information on physiological and psychological arousal. Psychopharmacology 157:373–380CrossRefPubMedGoogle Scholar
  12. Montgomery GH, Kirsch I (1997) Classical conditioning and the placebo effect. Pain 72:107–113CrossRefPubMedGoogle Scholar
  13. Nehlig A (1999) Are we dependent upon coffee and caffeine? A review on human and animal data. Neurosci Biobehav Rev 23:563–576PubMedGoogle Scholar
  14. O'Neill ST, Parrott AC (1992) Stress and arousal in sedative and stimulant cigarette smokers. Psychopharmacology 107:442–446PubMedGoogle Scholar
  15. Phillips-Bute BG, Lane JD (1998) Caffeine-withdrawal symptoms following brief caffeine deprivation. Physiol Behav 63:35–39CrossRefGoogle Scholar
  16. Price DD, Milling LS, Kirsch I, Duff A, Montgomery GH, Nicholls SS (1999) An analysis of factors that contribute to the magnitude of placebo analgesia in an experimental paradigm. Pain 83:147–156CrossRefPubMedGoogle Scholar
  17. Schicatano EJ, Blumenthal TD (1995) The effects of different doses of caffeine on habituation of the human acoustic startle reflex. Pharmacol Biochem Behav 52:231–236PubMedGoogle Scholar
  18. Smith AW, Whitney H, Thomas M, Perry K, Brockman P (1997) Effects of caffeine and noise on mood, performance and cardiovascular functioning. Hum Psychopharmacol 12:27–33Google Scholar
  19. Walach H, Schmidt S, Dirhold T, Nosch S (2002) Effects of a caffeine placebo and suggestion on blood pressure, heart rate, well-being, and cognitive performance. Int J Psychophysiol 43:247–260CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • Magne Arve Flaten
    • 1
  • Ole Aasli
    • 1
  • Terry D. Blumenthal
    • 2
  1. 1.Department of Psychology, SV-FakUniversity of TromsøTromsøNorway
  2. 2.Department of PsychologyWake Forest UniversityWinston SalemUSA

Personalised recommendations